package com.studymaster.util;


public class Escape {

	private final static String[] hex = { "00", "01", "02", "03", "04", "05",
		"06", "07", "08", "09", "0A", "0B", "0C", "0D", "0E", "0F", "10",
		"11", "12", "13", "14", "15", "16", "17", "18", "19", "1A", "1B",
		"1C", "1D", "1E", "1F", "20", "21", "22", "23", "24", "25", "26",
		"27", "28", "29", "2A", "2B", "2C", "2D", "2E", "2F", "30", "31",
		"32", "33", "34", "35", "36", "37", "38", "39", "3A", "3B", "3C",
		"3D", "3E", "3F", "40", "41", "42", "43", "44", "45", "46", "47",
		"48", "49", "4A", "4B", "4C", "4D", "4E", "4F", "50", "51", "52",
		"53", "54", "55", "56", "57", "58", "59", "5A", "5B", "5C", "5D",
		"5E", "5F", "60", "61", "62", "63", "64", "65", "66", "67", "68",
		"69", "6A", "6B", "6C", "6D", "6E", "6F", "70", "71", "72", "73",
		"74", "75", "76", "77", "78", "79", "7A", "7B", "7C", "7D", "7E",
		"7F", "80", "81", "82", "83", "84", "85", "86", "87", "88", "89",
		"8A", "8B", "8C", "8D", "8E", "8F", "90", "91", "92", "93", "94",
		"95", "96", "97", "98", "99", "9A", "9B", "9C", "9D", "9E", "9F",
		"A0", "A1", "A2", "A3", "A4", "A5", "A6", "A7", "A8", "A9", "AA",
		"AB", "AC", "AD", "AE", "AF", "B0", "B1", "B2", "B3", "B4", "B5",
		"B6", "B7", "B8", "B9", "BA", "BB", "BC", "BD", "BE", "BF", "C0",
		"C1", "C2", "C3", "C4", "C5", "C6", "C7", "C8", "C9", "CA", "CB",
		"CC", "CD", "CE", "CF", "D0", "D1", "D2", "D3", "D4", "D5", "D6",
		"D7", "D8", "D9", "DA", "DB", "DC", "DD", "DE", "DF", "E0", "E1",
		"E2", "E3", "E4", "E5", "E6", "E7", "E8", "E9", "EA", "EB", "EC",
		"ED", "EE", "EF", "F0", "F1", "F2", "F3", "F4", "F5", "F6", "F7",
		"F8", "F9", "FA", "FB", "FC", "FD", "FE", "FF" };

	private final static byte[] val = { 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x00, 0x01,
		0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
		0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F };

	/**
	 * 编码
	 *
	 * @param s
	 * @return
	 */
	 public static String escape(String s) {
		StringBuffer sbuf = new StringBuffer();
		int len = s.length();
		for (int i = 0; i < len; i++) {
			int ch = s.charAt(i);
			if ('A' <= ch && ch <= 'Z') { // 'A'..'Z' : as it was
				sbuf.append((char) ch);
			} else if ('a' <= ch && ch <= 'z') { // 'a'..'z' : as it was
				sbuf.append((char) ch);
			} else if ('0' <= ch && ch <= '9') { // '0'..'9' : as it was
				sbuf.append((char) ch);
			} else if (ch == '-'
				|| ch == '_' // unreserved : as it was
					|| ch == '.' || ch == '!' || ch == '~' || ch == '*'
						|| ch == '\'' || ch == '(' || ch == ')') {
				sbuf.append((char) ch);
			} else if (ch <= 0x007F) { // other ASCII : map to %XX
				sbuf.append('%');
				sbuf.append(hex[ch]);
			} else { // unicode : map to %uXXXX
				sbuf.append('%');
				sbuf.append('u');
				sbuf.append(hex[(ch >>> 8)]);
				sbuf.append(hex[(0x00FF & ch)]);
			}
		}
		return sbuf.toString();
	 }

	 /**
	  * 解码 说明：本方法保证 不论参数s是否经过escape()编码，均能得到正确的“解码”结果

	  *
	  * @param s
	  * @return
	  */
	 public static String unescape(String s) {
		 s=s==null?"":s.trim();
		 StringBuffer sbuf = new StringBuffer();
		 int i = 0;
		 int len = s.length();
		 while (i < len) {
			 int ch = s.charAt(i);
			 if ('A' <= ch && ch <= 'Z') { // 'A'..'Z' : as it was
				 sbuf.append((char) ch);
			 } else if ('a' <= ch && ch <= 'z') { // 'a'..'z' : as it was
				 sbuf.append((char) ch);
			 } else if ('0' <= ch && ch <= '9') { // '0'..'9' : as it was
				 sbuf.append((char) ch);
			 } else if (ch == '-'
				 || ch == '_' // unreserved : as it was
					 || ch == '.' || ch == '!' || ch == '~' || ch == '*'
						 || ch == '\'' || ch == '(' || ch == ')') {
				 sbuf.append((char) ch);
			 } else if (ch == '%') {
				 int cint = 0;
				 if ('u' != s.charAt(i + 1)) { // %XX : map to ascii(XX)
					 cint = (cint << 4) | val[s.charAt(i + 1)];
					 cint = (cint << 4) | val[s.charAt(i + 2)];
					 i += 2;
				 } else { // %uXXXX : map to unicode(XXXX)
					 cint = (cint << 4) | val[s.charAt(i + 2)];
					 cint = (cint << 4) | val[s.charAt(i + 3)];
					 cint = (cint << 4) | val[s.charAt(i + 4)];
					 cint = (cint << 4) | val[s.charAt(i + 5)];
					 i += 5;
				 }
				 sbuf.append((char) cint);
			 } else { // 对应的字符未经过编码
				 sbuf.append((char) ch);
			 }
			 i++;
		 }
		 return sbuf.toString();
	 }

	 public static void main(String[] args) {
		 String stest = "中文1234 abcd[]()<+>,.~\\";
		 System.out.println(stest);
		 System.out.println(escape(stest));
		 System.out.println(unescape(stest));
		 System.out.println(unescape("%u5355%u4F4D26"));
	 }
	 public static String gbEncoding(final String gbString) {
		 char[] utfBytes = gbString.toCharArray();
		 StringBuffer buffer = new StringBuffer();
		 for (int byteIndex = 0; byteIndex < utfBytes.length; byteIndex++) {
			 String hexB = Integer.toHexString(utfBytes[byteIndex]);
			 if (hexB.length() <= 2) {
				 hexB = "00" + hexB;
			 }
			 buffer.append("\\u" + hexB);
		 }
		 return buffer.substring(0);
	 }
	 /**
	  * unicode 转换成 中文
	  * 
	  * @author fanhui 2007-3-15
	  * @param theString
	  * @return
	  */
	 public static String decodeUnicode(String theString) {
		 char aChar;
		 int len = theString.length();
		 StringBuffer outBuffer = new StringBuffer(len);
		 for (int x = 0; x < len;) {
			 aChar = theString.charAt(x++);
			 if (aChar == '\\') {
				 aChar = theString.charAt(x++);
				 if (aChar == 'u') {
					 int value = 0;
					 for (int i = 0; i < 4; i++) {
						 aChar = theString.charAt(x++);
						 switch (aChar) {
						 case '0':
						 case '1':
						 case '2':
						 case '3':
						 case '4':
						 case '5':
						 case '6':
						 case '7':
						 case '8':
						 case '9':
							 value = (value << 4) + aChar - '0';
							 break;
						 case 'a':
						 case 'b':
						 case 'c':
						 case 'd':
						 case 'e':
						 case 'f':
							 value = (value << 4) + 10 + aChar - 'a';
							 break;
						 case 'A':
						 case 'B':
						 case 'C':
						 case 'D':
						 case 'E':
						 case 'F':
							 value = (value << 4) + 10 + aChar - 'A';
							 break;
						 default:
							 throw new IllegalArgumentException(
									 "Malformed      encoding.");
						 }
					 }
					 outBuffer.append((char) value);
				 } else {
					 if (aChar == 't') {
						 aChar = '\t';
					 } else if (aChar == 'r') {
						 aChar = '\r';
					 } else if (aChar == 'n') {
						 aChar = '\n';
					 } else if (aChar == 'f') {
						 aChar = '\f';
					 }
					 outBuffer.append(aChar);
				 }
			 } else {
				 outBuffer.append(aChar);
			 }
		 }
		 return outBuffer.toString();
	 }
}
